The present invention is directed to a novel process for producing ethyl 3-ethoxypropanoate (EEP).
Ethoxyethyl acetate is a known industrial solvent having a wide variety of uses such as in coatings, paints, inks, etc. It is suspected, however, that ethoxyethyl acetate is a possible carcinogen. A potential non-carcinogenic substitute for ethoxyethyl acetate is believed to be ethyl 3-ethoxypropanoate (EEP).
Souther, in U.S. Pat. No. 2,386,363, describes the manufacture of EEP by heating a mixture of .beta.-ethoxypropionitrile and absolute ethanol with sulfuric acid and water in the following molar quantities 1:2:1:1 at a temperature of 99.degree.-105.degree. C. for from 12-24 hours.
Jones et al, in U.S. Pat. No. 4,827,021, describes the manufacture of alkyl 3-alkoxypropionates by the reaction of dialkoxy methane with a diketene. The catalyst for the reaction was methane disulfonic acid, methane trisulfonic acid, or mixtures thereof.
Brooks, U.S. Pat. No. 2,436,286, describes the reaction of dialkoxy methane with ketene in the presence of benzene sulfonic acid to form EEP and analogs thereof.
It is also known to produce EEP by the addition of ethanol to ethyl acrylate in the presence of a strong basic catalyst as is consistent with known methods, in general, of adding alcohols across the double bond of acrylate esters using strong bases as catalysts. Strong base catalysts which are useful in the formation of EEP include alkali metal alkoxides such as sodium ethoxide, potassium ethoxide and lithium ethoxide. While these catalysts have produced EEP in high efficiencies, the catalysts are extremely sensitive to moisture and readily deactivate in the presence of water. Accordingly, both the ethanol and ethyl acrylate reactants must be extremely dry. To provide the ethanol and ethyl acrylate reactants devoid of water is both a difficult and expensive process, thus, discouraging the manufacture and, thus, use of EEP. Examples of this reaction are to be found in Keen, U.S. Pat. No. 4,948,915, and the references cited therein.
Accordingly, it would be worthwhile to produce EEP in a manner which does not require the extensive preparation of the reactants to remove water and which can be done economically to meet the growing market for this non-carcinogenic solvent.